The Big Hammer Attack can only be used when Amy has Knuckles as her partner. Here, Amy must be the character the player controls, and Knuckles serves as the character that follows the controlled character. With Knuckles' influence, Amy's Hammer Attack is automatically transformed into the Big Hammer Attack.

When performing the Big Hammer Attack, Amy pulls out an oversized and massive version of Piko Piko Hammer and whacks the opponents in front of her with extreme force. In fact, the sheer force from the Big Hammer Attack's impact is so strong that it creates small tremors and allows Amy to break the metal barriers that appear throughout the stages.

The drawback of the Big Hammer Attack however, is that it takes much longer to be executed than a regular Hammer Attack, and therefore leaves Amy wide open and immobile for a short moment. It is therefore not advisable to use the Big Hammer Attack when fighting several enemies at once.